Black Hole
More than 10 billion years ago, when the cosmos was only about 3 billion years old and neither the Sun nor Earth existed yet, something in a distant galaxy unleashed an immense burst of radio energy. The pulse lasted only a few milliseconds. The radio waves then crossed roughly 80 % of cosmic history before arriving at our planet in March 2024.
Astronomers have now identified it as FRB 20240304B — the most distant fast radio burst ever localized. It more than doubles the previous distance record for these mysterious events. Fast radio bursts are brief, extremely bright radio pulses whose exact origins remain unknown. Most last from fractions of a millisecond to a few seconds and can release as much energy in that instant as the Sun does in days or longer. This one was first caught by the MeerKAT radio telescope array in South Africa. Follow-up imaging with the James Webb Space Telescope then pinpointed the host galaxy.
That galaxy turned out to be smaller and lower-mass than many earlier FRB hosts, metal-poor, clumpy, and vigorously forming stars. Its youth and low metallicity favor one leading explanation: a magnetar — the highly magnetized remnant core of a massive star that exploded as a supernova. Magnetars can form within a few million years after a star’s death, whereas other candidates (such as merging neutron stars) typically require billions of years. The early-universe setting therefore points strongly toward a magnetar origin for at least some FRBs. Because the signal traveled so far, it also carries information about the ionized gas and magnetic fields it passed through along the way. It gives astronomers a rare probe of conditions near “cosmic noon,” the epoch when star formation in the universe was at its peak. The discovery shows that the engines capable of producing these violent radio flashes were already active when the universe was still young, and it pushes the reach of localized FRBs deeper into cosmic history than ever before. Researchers are now using the event both to study the physics of the burst itself and as a cosmic yardstick for the matter distributed between galaxies.
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου